Add the chicken to a large bowl with the soy sauce, mirin, sesame oil, garlic, ginger, salt, white pepper and beaten egg. Toss until every piece is coated, then cover and refrigerate for 30 minutes to 1 hour.

Tip the cornstarch into a shallow dish. Working a few pieces at a time, lift the chicken out of the marinade and roll it in the cornstarch until fully coated, shaking off the excess. Set the coated pieces on a tray.

Preheat the air fryer to 200°C / 400°F. Leave the coated chicken to sit while it heats, until the coating looks damp rather than powdery.

Arrange the chicken in a single layer in the basket, working in batches. Air fry for 12 to 14 minutes, shaking the basket halfway, until golden, crisp and cooked through (75°C / 165°F in the thickest piece).

While the chicken cooks, whisk the mayonnaise, sweet chilli sauce, sriracha, soy sauce and lemon juice together in a large bowl.

Add the hot chicken to the sauce and toss until evenly coated. Serve straight away, scattered with spring onions and sesame seeds if you like.